Patent GB-331894-A (GB)
Title: Improvements in or relating to clutch mechanisms
IPC: F16D23/06
Filed: 1929-02-11
Abstract: 331,894. Humfrey, J. C. W., Hingston, W. H., and Humfrey-Sandberg Co., Ltd. Feb. 11, 1929. Facilitating changing speed ; clutches. - In clutches, particularly for use as tail clutches on motor vehicles, a bidirectional positive or friction clutch can 'be engaged and disengaged by means under the direct control of the operator and can be engaged automatically when the driving and driven shafts are rotating at approximately the same speed, such automatic engagement being operable without affecting the direct control means and also being lockable by said latter against operation. The gear-box shaft 4 carries a clutch drum 1 provided with teeth 2 for engagement by a clutch part 5 splined on the propeller shaft 6. The outer member 9 of a unidirectional ball or skewroller clutch 9, 15, such, for example , as is described in Specifications 239,594, 248,183, and 286,389, in which relative axial movement of the members takes place during change from drive to free-wheeling and vice versa, is splined to the drum 1 and pressed axially by springs 11 to freewheeling position. The clutch-member 15 is secured to the shaft 6. A loose baulking-ring 18 bears frictionally against the member 9, if desired by coned surfaces, and has inclined faces 22 engaging balls 25 bearing upon a flat face 24 of an abutment ring 19 fast on the shaft. Alternatively, the ring 19 also may have inclined faces, when the balls may be omitted. The ring 18 carries pins 27 provided with notches 29, Fig. 2, engaging the edges of holes 28 in the clutch member 5 when the shaft 6 is overrunning the shaft 4, so preventing re-engagement of the clutch 5, 2. When the shaft 4 speeds up so as slightly to overrun the shaft 6, the ring 18 is rotated forwardly by friction with the member 9 so that wedging action between the rings 18, 19 produces end movement of the ring 18 to press the member 9 to position to drive the member 15 through the skew rollers. Practically simultaneously, the pins 27 are allowed to enter the holes 28 and permit engagement of the clutch 5, 2 by a spring 30. A shift-lever 8 has a pin-and-slot connection, such as is used in the construction shown in Fig. 11, with a hand-lever which can be moved to disengage the clutch 5, 2 or to effect engagement upon synchronism, or can be so set as either to prevent or not to hinder the automatic engagement. Further it can be operated to move the member 5 beyond its central position to engage teeth 2<1> on the drum 1 so as to connect the shafts positively, as for reverse, at any time. When the shaft 6 is overrunning and the parts lie as shown in Fig. 2, end pressure by the hand lever upon the member 5 will press the one-way clutch parts into frictional engagement. The member 15 and the skew rollers may be dispensed with, the elements 9, 18, 25, 19 themselves acting as a unidirectional clutch between the shafts 4, 6. In the modification shown in Figs. 4, 5 and 10, the member 9 and baulking-ring 18 carrying interengaging cone surfaces 46, 45, or a cylindrical drum and radially spring-pressed segments, respectively, and the clutch spring 30 bears on a ring 75 carrying pins 42 which slide in the clutch part 5 and abutment ring 19 and engage with the hub 64 of the ring 18, the parts being formed as shown in Fig. 5 both to produce axial movement of the ring 18 to engage the one-way clutch and to allow axial movement of the pins 42 when the shaft 4 slightly overruns the shaft 6, so that the spring 30 presses the ring 75 against the clutch part 5 and engages the claw clutch. Disengagement of the claw clutch at any time, and engagement upon synchronism, may be effected by a hand-lever 116, Fig. 10, having a pin-and-slot connection with an arm 89 on a rock-shaft 78 carrying a shift-arm 71 engaging the clutch part 5. A second shift-arm 77 engages the ring 75 and is operated by a cam 83 on a shaft 82 operable from the engine clutch pedal, which shaft is axially shiftable by a Bowden wire to move a second cam 80 carried thereby into the path of an arm 79 on the shaft 78. The parts are so arranged that according as the tail-shaft clutches have been engaged automatically or are engaged by the lever 116, disengagement of the main engine clutch disconnects or does not affect the claw clutch 5, 2. For this purpose, a rod 88 connected to the engine clutch pedal is provided with a slotted end 187 engaging a pin 87 on an arm 86 secured to the cam shaft 82. The lever 116 carries an extension 90 which, when the claw clutch 5, 2 is put into engagement by the lever 116, lifts the rod 88 so that the pin 87 lies on the lower slot of the rod end 187, and th,e clutch 5, 2 is unaffected by movement of the engine clutch pedal. The hand-lever 116 may be used to re-engage the claw clutch at any time except when the cam 80 is pressed by movement of the engine clutch pedal against the arm 79 to disengage the claw clutch, and can be used otherwise as is the hand-lever used in the construction shown in Fig. 1. In these clutch-shifting operations, the ring 75 need not be moved. If the clutch 5, 2 is disengaged by the lever 116, the rod 88 falls, and, if the engine has stopped, the cam shaft 82 may be moved axially to bring the cam 83 into the path of the lever 77, when depression of the engine clutch pedal presses the ring 75 axially and jams the rollers of the oneway clutch into frictional contact with their races, so that, due to this jamming action and the friction of the cone surfaces 46, 45, the shaft 4 is speeded up and starts the engine, which will then assist to speed up the shaft 4 sufficiently to enable the clutch 5, 2 to be engaged without shock by movement of the hand-lever 116. In the construction shown in Fig. 11, a disc 90 bears frictionally upon a drum 92 secured to the driving-shaft and has internal teeth engaged by notched teeth on the end of a sleeve 95, which is splined to the driven shaft 94 and is pressed by a spring 98 against a flange 97 on the sliding clutch part 5, which may alternatively be of cone type. The part 5 is engaged by a shift-lever 103 which carries an extension 104 with a pin 108 engaging in a slot 109 in a hand-lever 105 turning on the same pivot 107 as a lever 103, 104. The pin 108 also engages in the slotted end 110 of a rod 106 linked to the engine clutch pedal. When the clutch 5 has been automatically engaged by the spring 98, the disengagement of the engine clutch operates the lever 104 to disengage the clutch 5. The clutch 5 may, however, be engaged at any time by the hand-lever 105, whereupon a pin 111 thereon lifts the rod 106 so that the pin 108 enters the lower part of the end 110, and the engine clutch can then be disengaged without affecting the clutch 5. The hand-lever 105 can be used otherwise for controlling the clutch action as is described in connection with Fig. 1.